An anti-whaling protest ship reports it's in the midst of a conflict with a Japanese whaling ship in the Ross Sea on Friday morning.
Sea Shepherd captain Paul Watson says a Japanese ship killed a whale and its crew were cutting up the meat.
Mr Watson says his group threw butter bombs on to the deck of the ship to try to deter the crew from continuing their work.
He hopes the odour from the bombs will taint the whale meat, so it cannot be sold.
He says the protests will continue until the ship's fuel supplies run out in a few weeks.
On Thursday, Mr Watson said three harpoon boats from the Nissan Maru tried to ram his ship and disable its propeller.
He said the whalers also used a device that sends out sound waves.
It was also pointed at a helicopter filming the incident for Sea Shepherd purposes.